UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION IX AIR DIVISION

Technical Support Document 

for

EPA’s Notice of Direct Final Rulemaking

for the

California State Implementation Plan

Yolo-Solano Air Quality Management District

Rule 2.41, Expandable Polystyrene Manufacturing Operations

July 28, 2011

Prepared by Mae Wang
2

Agency: Yolo-Solano Air Quality Management District (YSAQMD)

SIP Approved Rule:

none

Previously Submitted Versions:

none

Subject of this Technical Support Document:

YSAQMD Rule 2.41, Expandable Polystyrene Manufacturing Operations

Adopted on September 10, 2008, submitted on December 23, 2008

Rule Summary 

Rule 2.41 was designed to control emissions of volatile organic compounds (VOC) from 

the manufacturing of expandable polystyrene (EPS) products. The rule requires all 

manufacturing emissions to be controlled by an emission control system with a capture efficiency 

of at least 90% and a destruction efficiency of at least 95%. The rule also requires all EPS 

products to be manufactured with either low-pentane or mid-pentane beads. Compliance with 

these requirements is verified through yearly source testing and daily records of raw material 

usage, emissions control system operating parameters, and finished product specifications. 

Currently, there is only one EPS product manufacturing facility in YSAQMD. 

EPA Evaluation

Generally, SIP rules must be enforceable (see section 110(a) of the Clean Air Act

(CAA)), must require Reasonably Available Control Technology (RACT) for major sources in 

nonattainment areas (see section 182(a)(2)(A) of the CAA), must not relax existing requirements. 

The YSAQMD regulates a severe ozone nonattainment area (40 CFR 81), so Rule 2.41 must 

fulfill RACT as well as CAA section 110(l) requirements. 

Guidance and policy documents that we used to evaluate the submitted rule include the 

following:

1. Issues Relating to VOC Regulation Cutpoints, Deficiencies, and Deviations, EPA, May 

25, 1988 (The Bluebook).

2. Guidance Document for Correcting Common VOC & Other Rule Deficiencies, EPA 

Region 9, August 21, 2001 (the Little Bluebook).
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3. “Control of VOC Emissions from Polystyrene Foam Manufacturing” (EPA-450/3-90-020, 

September 1990).

4. SIP Relaxation - Where previous versions of rules have been SIP approved, new 

submittals must comply with CAA §110(l) and §193 regarding SIP relaxations. We 

evaluate SIP revisions to determine whether they would interfere with any applicable 

requirement concerning attainment and reasonable further progress (RFP) or any other 

applicable requirement of the CAA (see CAA section 110(l)) or modify, in a 

nonattainment area, any SIP-approved control requirement in effect before November 15, 

1990 (see CAA section 193).

YSAQMD Rule 2.41 fulfills the relevant criteria summarized above. This rule improves 

the SIP by regulating a source category for which no previous SIP rule exists. The rule is 

generally clear and contains appropriate monitoring, reporting, and recordkeeping requirements 

to ensure the emission limits are adequately enforceable. The rule does not interfere with any 

applicable requirement concerning attainment and RFP or any other applicable requirement of 

the CAA (see section 110(l) of the CAA). The rule requirements are generally consistent with 

the recommendations contained in EPA’s control technology documents and other district rules 

regulating the same category of sources. We are not aware of any more stringent controls 

demonstrated to be reasonably available for this industry. 

Additional Recommendations 

The following suggested revisions are not currently the basis for rule disapproval, but are 

recommended for the next time the rule is amended. 

 

Because of the high quantities of emissions from the storage areas in these types of facilities, we 

recommend that the YSAQMD require controls during the storage and aging processes. Since 

there is only one facility in the YSAQMD, it would be possible to evaluate this situation on a 

case-by-case basis. Some facilities in other districts have installed control systems for the 

storage areas, and South Coast AQMD Rule 1175 contains language establishing requirements 

for these areas. We are aware that the control of emissions from these large warehouses may 

require building alterations and may initially be viewed as cost-prohibitive, but in some facilities 

the changes and installation of controls was determined to be technically and economically 

feasible. 

EPA Action

YSAQMD Rule 2.41 strengthens the SIP and fulfills the relevant Clean Air Act §110 and 

Part D requirements. EPA staff recommends approval of Rule 2.41 pursuant to CAA §110(k)(3).